In the Musician's Brain, Sometimes Less is More

March 2, 2016
Ketki Karanam

Study finds less gray matter in brain areas involved in control of movement and sound processing in musicians

Conventional wisdom says that in order to become very good at a demanding task such as playing a musical instrument, you have to start young. Indeed, several neuroimaging studies have reported that training-related changes in brain structure are most pronounced in musicians who have started early. However, is it the age at which you start learning this skill that matters, or only the fact that if you start practicing young, you spend more years practicing? Is there an optimum age when a child should start practicing an instrument to attain the biggest benefits?

A few studies have taken the total amount of practice into account and have still found more pronounced structural changes in the brains of early starters. This means music training may have a more profound impact on the brain if practice starts at a young age. The most recent addition to this line of research is a study that compared brain structure between highly trained pianists and non-musician controls, and also examined whether the age of onset of training was linked to changes in brain structure within the musician group. As is conventional in this field of inquiry, the researchers grouped pianists who had started before the age of 7 into early starters, and those who had started after the age of 7 into late starters.

The study found the early starters performed a musical scale exercise with slightly more accurate timing than the late starters, especially with the non-dominant left hand. With regard to brain structure, the study found that in comparison to control (non-musician) participants, the pianists showed more gray matter in several brain areas related to learning, sound processing and - perhaps more surprisingly - visual processing. According to the authors, the latter finding might be related to musicians’ extensive experience in score reading and finding notes on the keyboard. These findings are well in line with a substantial amount of previous music training research showing that learning to play an instrument is linked with increases in gray matter in several brain areas. Thus it would seem that in the musician brain more neural resources are allocated to functions that are important for music perception and production.

This is not the whole story, however. Interestingly, the study also found less gray matter in brain areas involved in control of movement and sound processing in musicians than in the non-musician group. Intuitively it would seem that more is more: the more you practice, the more gray matter increases in brain areas important for the skill you are honing. The authors explain this counter-intuitive finding of decreased gray matter in terms of neural efficiency. That is, the musicians’ brains might have become more efficient at some tasks and thereby use fewer neurons for these tasks than the non-musicians. In other words, perhaps the musician brain can do some tasks better than non-musicians, while using less brain resources! In fact, such optimization of brain usage is not an uncommon finding. For instance, similar decreases in gray matter in areas important for a highly practiced skill have previously been found.

Is there an optimum age when a child should start practicing an instrument to attain the biggest benefits?

In summary, the study suggests that in addition to increases in gray matter, musical training may also induce decreases in gray matter. To this date there is no definite answer to why we sometimes find more and sometimes less gray matter in the brains of musician when compared to the brains of non-musicians. Such uncertainty can be a source of frustration to some but can also be seen as a new and exciting area of inquiry. In fact, we don’t yet know what increased gray matter volume seen by MRI means at a more fine-grained level (More neurons? More glial cells? More blood vessels? For a review, see here. Future studies will hopefully help scientists get a more detailed look at such micro-level changes.

Finally, according to the results of the study, this optimized use of neural resources is more evident in the brains of musicians who started training early, before the age of 7. However, it should be noted that although age 7 is a conventional cut-off point for dividing subjects into early and late starters in neuroimaging studies, this age should not be taken as some magical borderline after which all is lost if you want to become a musician. After all, the late starters in the study were also highly skilled professional pianists! In fact, recent studies indicate that making and enjoying music has many benefits irrespective of age and the amount of formal musical training. But in terms of neuroplasticity, sometimes less is more.